CVE-2021-0464
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedIn sound_trigger_event_alloc of platform.h, there is a possible out of bounds write due to a heap buffer overflow. This could lead to local escalation of privilege with no additional execution privileges needed. User interaction is not needed for exploitation.Product: AndroidVersions: Android kernelAndroid ID: A-167663878
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · high confidenceHeap buffer overflow vulnerability in Android kernel's sound_trigger_event_alloc function in platform.h allows a local attacker to write beyond allocated buffer boundaries, leading to local privilege escalation without requiring additional execution privileges or user interaction.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE dataall versionsCVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Local
- Complexity
- Low
- Privileges
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Check Android security patch levelGo to Settings > About Phone > Security Patch Level and note the date. For CVE-2021-0464, the fix was released in the Android Security Bulletin dated May 2021 or later.Affected if The Security Patch Level is earlier than May 2021 or the patch level is unknown/unavailable.
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Verify Android version and kernel versionGo to Settings > About Phone to view Android version. Check kernel version via 'cat /proc/version' in terminal or ADB shell.Affected if The Android version is any version (according to the advisory, all versions are affected prior to patching).
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Confirm sound trigger subsystem is accessibleCheck if /dev/sound_trigger device node exists (ls -la /dev/sound_trigger) or if sound trigger HAL service is running (getprop | grep soundtrigger).Affected if The sound trigger subsystem is present and accessible on the device.
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Check for presence of vulnerable function in kernelIf root access is available, examine the kernel image or system library for the sound_trigger_event_alloc function in platform.h header or examine /sys/kernel/debug/vmalloc for loaded kernel modules containing this symbol.Affected if The vulnerable function exists without bounds checking fixes applied.
A device is affected if it has not received the May 2021 or later Android security patch and the sound trigger subsystem is present on the device.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataApply Android kernel security patches; this vulnerability requires a fix in the sound trigger subsystem with proper bounds checking in the sound_trigger_event_alloc function.
- Consultation3.0 h
- Implementation4.0 h
- Testing6.0 h
- Review / QA3.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-0464 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2021-0464 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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